In various industries there is a need for sensor packages that are able to detect changes in materials passing between a signal generator and a detector at a high rate of speed. For example, a user may wish to count a number of adhesive labels affixed to a strip of backing paper while running a sheet of backing paper with adhesive labels affixed to one side through a sensor package. By sensing the change in transparency between the label and the backing paper, the sensor package may detect each label as it passes between the signal generator (e.g., a light emitting diode) and the detector (e.g., a photodectector).
The change that the sensor package is looking for may be extremely small, requiring very sensitive detection. In some applications, this change may be small enough that variances in manufacture of parts of the sensor package, variances in temperature of the sensor package, variations in the path of the materials as they pass through the sensor package, etc. could result in errors in detection. It is therefore necessary to calibrate the sensor package to the particular environment it is being used in and with the particular components that the sensor package has been assembled from. Typically, this calibration is done manually and one time permanent adjustments are made to the sensor package based on testing in the target environment. It is therefore desirable to improve upon this method of calibration.